Tribological Behaviors of Polymer Based Composites under Alkaline Conditions

2012 ◽  
Vol 510 ◽  
pp. 563-568
Author(s):  
Yan Ji Zhu ◽  
Hui Juan Qian ◽  
Gui Ying Wang ◽  
Huai Yuan Wang
Keyword(s):  
Wear Resistance ◽  
Frame Structure ◽  
Alkaline Condition ◽  
Wear Properties ◽  
Friction Coefficients ◽  
Wear Rates ◽  
Transfer Films ◽  
Peek Composite ◽  
Alkaline Conditions ◽  
Ptfe Composites

In this paper, polyetheretherketone (PEEK) and polytetrafluoroethylene (PTFE) based composites reinforced with various amounts of potassium titanate whiskers (PTWs) or short carbon fibers (CF) were designed and fabricated respectively. The friction and wear properties of PEEK and PTFE based composites sliding under rigorous alkaline were comparatively investigated. Also, the morphologies of the worn and counterpart surfaces were studied by scanning electron microscopy (SEM). Because of the stable tunnel crystal structure and frame structure micro-reinforcement capacity, PTWs show outstanding performances in increasing the wear resistance and reducing the friction coefficients of both PEEK and PTFE based composites under alkaline. However, CF leads to the degradation of wear resistance and the increase of friction coefficient of PEEK based composites under alkaline. Furrows and abrasive wear were the main mechanisms for CF/PTFE/PEEK and CF/PTFE composites sliding in alkali. The results show that PTW/PTFE composites exhibit higher wear resistance under lower load, while PTW/PTFE/PEEK composite is more suitable for higher load under alkaline condition. Owing to the primary cooling and boundary lubricating effects of alkali, the wear rates and friction coefficients of PTFE composites and PTW/PTFE/PEEK composites decreased obviously, though the transfer films onto the counterpart steel surface were hindered considerably.

Wear Properties of Y-TZP Ceramics Dispersed with Second Phase Particles

2008 ◽  
Vol 368-372 ◽  
pp. 744-747
Author(s):  
Xiao Ping Liang ◽  
Shao Bo Xin ◽  
Xiao Hui Wang ◽  
Zheng Fang Yang
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Mass Fraction ◽  
Normal Load ◽  
Roller Bearing ◽  
Second Phase ◽  
Wear Properties ◽  
Wear Rates ◽  
Second Phase Particles ◽  
Better Than

The wear properties of ADZ (alumina dispersed in Y-TZP) and MDZ (mullite dispersed in Y-TZP) were investigated by using a ring-on-block tribometer. The results showed that for Y-TZP ceramic, the addition of alumina phase (with 10-20% in mass fraction) leads to an improved wear resistance. With the increase of the normal load, the wear rates of ADZ ceramics increase. Under low and medium normal load (100N and 300N), the wear resistance is controlled by the hardness of ceramics, and under high normal load (500N) the fracture toughness is obviously contributed to the wear resistance of the ceramics. For MDZ ceramic, the wear resistance of 15MDZ (15wt% mullite dispersed in Y-TZP) is better than that of 20 MDZ (20wt% mullite) under the normal load from 100 N to 500 N. The mechanical properties of 15MDZ are worse than that of Y-TZP ceramic, but the wear resistance is enhanced due to the action of “needle roller bearing” of the fractured rod-like mullite particles.

MICROSTRUCTURE AND WEAR PROPERTIES OF LASER CLAD TiB2 + TiC/Fe COMPOSITE COATING

2012 ◽  
Vol 19 (05) ◽  
pp. 1250052 ◽  
Author(s):  
X. H. WANG ◽  
M. ZHANG ◽  
B. S. DU ◽  
S. LI
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
Volume Fraction ◽  
Composite Coatings ◽  
Wear Properties ◽  
Friction Coefficients ◽  
Iron Based

Iron-based composite coatings reinforced with TiB2–TiC multiple ceramic have been fabricated from a precursor of B4C , TiO2 and Al powders by laser cladding. The effect of TiO2 and Al on the microstructure and wear properties of the coatings was investigated. The results showed that the volume fraction, type and size of the reinforcements were influenced by the content of TiO2 and Al . TiB2 and TiC were evenly distributed in the coating; however, most of Al2O3 were ejected from the coatings, only few of them retained in the coating acting as nucleation core of reinforcement or inclusion. The microhardness and wear resistance of the coatings were improved, whereas the friction coefficients of the coatings were considerably lower than that of substrate.

Tribological behavior and morphology of PTFE particulate-reinforced POM matrix composites

2017 ◽  
Vol 37 (3) ◽  
pp. 227-237 ◽  
Author(s):  
Qi Liu ◽  
Wei Luo ◽  
Shengtai Zhou ◽  
Huawei Zou ◽  
Mei Liang
Keyword(s):  
Wear Resistance ◽  
High Speed ◽  
Friction And Wear ◽  
Thermodynamic Characteristics ◽  
Special Focus ◽  
Wear Properties ◽  
Scanning Calorimetry ◽  
Sliding Speed ◽  
Friction And Wear Properties ◽  
Ptfe Composites

Abstract The friction and wear properties of polyoxymethylene/polytetrafluoroethylene (POM/PTFE) composites were investigated by using a block-on-ring friction tester and special focus was paid to the effect of weight average molar mass (Mw) of POM. To study the thermodynamic characteristics and wear mechanism of composites, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were used. Results showed that friction and wear properties of the composite blends were strongly affected by the Mw of POM and the loading fractions of PTFE. POM/PTFE composites with lower Mw of POM owned better wear resistance abilities under a high-speed sliding regime, which resulted from the effective lubrication of transferred wear debris under a relatively high sliding speed. However, the transfer layer on the counterface could be easily peeled off under the low sliding speed, resulting in higher wear rate of POM/PTFE composites with lower Mw of POM. POM and its composites with high Mw showed comparative high friction levels, related to the strong adhesion between the resin and the steel counterpart. DSC analysis showed that POM with lower Mw had higher crystallinity, which was beneficial to the improvement of wear resistance in a high-speed sliding condition.

Wear Resistance Improvement by Nanostructured Surface Layer Produced by Burnishing

2018 ◽  
Vol 917 ◽  
pp. 231-235 ◽  
Author(s):  
Hirotaka Kato ◽  
Hiroto Ueki ◽  
Keitaro Yamamoto ◽  
Kazufumi Yasunaga
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Carbon Steel ◽  
Rotating Disk ◽  
Dry Sliding Wear ◽  
Wear Properties ◽  
Surface Layers ◽  
Wear Rates ◽  
Strain And Strain Rate ◽  
Burnishing Process

Burnishing, which is one of the most powerful processes for microstructural evolution, was performed by a cemented carbide ball (6 mm in diameter) that was loaded and fed on the flat surface of a rotating disk specimen of carbon steel using a lathe machine. The effects of burnishing process parameters such as force and rotation speed on the surface roughness, microstructure and hardness were investigated. In addition the dry sliding wear properties of the burnished surface layers were studied using a ball-on-disk friction method. It was found that the burnished surface was much smoother than as-turned surface (before burnishing) owing to the plastic flow of the surface asperities through the rubbing motion of the burnishing ball. Nanostructure in the 30 - 50 nm grain size range was formed in the burnished sub-surface layer, and the hardness significantly increased due to the grain refinement. The nanocrystalline microstructure was observed at high burnishing forces and speeds owing to the high strain and strain rate of the friction-induced plastic deformation. Moreover the burnishing process reduced the specific wear rates by a factor of six. Thus we concluded that the wear resistance of carbon steel can be significantly improved by burnishing due to the smooth surface and nanostructured sub-surface layers.

Friction and Wear Properties of Fe7Mo6-Based Alloy under Various Sliding Conditions

2012 ◽  
Vol 706-709 ◽  
pp. 1083-1088
Author(s):  
Takashi Murakami ◽  
Kunio Matsuzaki
Keyword(s):  
High Temperatures ◽  
Friction And Wear ◽  
Testing Temperature ◽  
Wear Properties ◽  
Friction Coefficients ◽  
Rich Phase ◽  
Wear Rates ◽  
Friction And Wear Properties ◽  
Worn Surface ◽  
Friction And Wear Tests

In this study, the friction and wear properties of the Fe7Mo6-based alloy/Al2O3 tribopair were investigated at high temperatures in air and at 298 K in water. The Fe7Mo6-based alloy/Al2O3 tribopair exhibited friction coefficients as low as 0.5 at 298 K and 873 K in air. On the other hand, this tribopair exhibited higher friction coefficients at 573 K than at 298 K and 873 K. It was also found that the friction coefficients of this tribopair were approximately 0.5 in water. The Fe7Mo6-based alloy disk specimens and their paired Al2O3 ball specimens exhibited the highest specific wear rates at 873 K in air. Oxygen-rich phase was observed on the worn surfaces of all the disk specimens. Concerning the friction and wear tests at high temperatures in air, the amount of the oxygen-rich phase increased with increasing the testing temperature. In addition, a little larger amount of the oxygen-rich phase was observed on the worn surface formed at 298 K in water than that formed at 298 K in air.

Influence of SiO2/MoS2/graphite content on the wear properties of PTFE composites under natural seawater lubrication

2018 ◽  
Vol 232 (5) ◽  
pp. 607-618 ◽  
Author(s):  
Zhiqiang Wang ◽  
Shaofeng Wu ◽  
Jing Ni
Keyword(s):  
Wear Resistance ◽  
Laser Scanning ◽  
Natural Seawater ◽  
Wear Properties ◽  
Laser Scanning Confocal Microscope ◽  
Ptfe Composite ◽  
Seawater Lubrication ◽  
Friction Energy ◽  
Ptfe Composites ◽  
Test Table

The polytetrafluroethylene (PTFE) mixed with different particles, such as SiO2, MoS2, and graphite, were prepared by using cold briquetting and hot sintering technologies. In order to investigate the influence of different mixture ratios of particles on the wear properties of PTFE composite under natural seawater lubrication, 10 different samples were designed through orthogonal test table and evaluated using an MMU-5 G wear tester. For comparison, the wear experiments of pure PTFE were also carried out under the same conditions. Moreover, the 3D profiles and depth variations of wear scars of PTFE composites were observed by a laser scanning confocal microscope. Results showed that the addition of SiO2, MoS2, and graphite can greatly improve the wear resistance of PTFE under seawater lubrication. In particular, 10% SiO2, 15% MoS2, and 15% graphite filled with PTFE composite possesses the best wear resistance. And a synergistic effect is found for the combination of SiO2, MoS2, graphite, and seawater, which effectively prevents the slipping of PTFE from matrix, increases the adhesion resistance, decreases the friction energy, further results in lower wear rate and little damage on the surface of the PTFE composites.

Effect of fiber type, fiber content, and compatibilizer on two-body abrasive wear performance of HDPE matrix composites

2019 ◽  
Vol 53 (19) ◽  
pp. 2743-2760
Author(s):  
Soner Savaş ◽  
Nurlan Gurbanov ◽  
Mehmet Doğan
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Fiber Type ◽  
Basalt Fiber ◽  
Point Of View ◽  
Vacuum System ◽  
Wear Properties ◽  
Fiber Concentration ◽  
Wear Rates ◽  
Pin On Disc

This study puts forth the synergistic effect of fiber concentration and maleic anhydride-grafted polyethylene (PE-g-MA) compatibilization on the abrasive wear properties of high-density polyethylene (HDPE) composites. Composites including carbon, basalt, jute and coconut short fibers with different weight ratios were processed by melt blending and then tested by using a pin-on-disc abrasive wear tester in dry sliding conditions. The test rig was also equipped with a vacuum system, for the first time, to promote two-body abrasive wear of the composites by reducing the wear debris which may be trapped in the wear track and alter the wear properties. In addition, fiber and coupling agent concentrations and test parameters were investigated using L16 full-factorial experimental design and the relationships between these parameters and wear behaviors of the composites were analyzed on the basis of the findings. This work clearly shows that high rigidity obtained by fiber contribution was not beneficial from the abrasive wear resistance point of view, due to repeated plowing effect of the counterpart material under the test conditions. Nevertheless, basalt fiber-reinforced composites showed higher wear resistance than other composites. Except for coconut fibers, PE-g-MA exhibited good miscibility between fibers and matrix, and thus an enhancing effect on the hardness values, and also wear resistance of the samples. Briefly, the rigidity and miscibility of the composites were found in balance for optimum wear rates.

scholarly journals The Tribological and Sealing Properties of PFA Composites

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Ye Sujuan ◽  
Yu Quan ◽  
Li Kunquan ◽  
Tan Feng ◽  
Fan Qing ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Carbon Fiber ◽  
Wear Rate ◽  
Glass Fiber ◽  
Vinyl Ether ◽  
Transfer Film ◽  
Test Rig ◽  
Wear Rates ◽  
Ptfe Composite ◽  
Ptfe Composites

The polytetrafluoroethylene (PTFE) and perfluoroalkoxyperfluoropropyl vinyl ether (PFA) composites were prepared using carbon fiber (CF) and glass fiber (GF) as fillers. The effects of these fillers on the tribological and sealing properties were investigated. The tribological and sealing properties of the composites were evaluated by a wear tester and a seal test rig. Results showed that the incorporation of CF and GF both improved the wear resistance with composites, approaching wear rates as low as 10−6 mm3/N·m and lowered the seal’s leakage of the PTFE/PFA composites. As described here, CF was more effective than GF in improving the wear rate. Notably, the wear rate of the PFA/CF composite is much less than that of the PTFE composites as the transfer film on the couple ring is much more unique, thick, smooth, and compact. The leakage of carbon fiber-filled PFA composite seal was lowered to 66% less than the traditional PTFE composite seals, which indicates better sealing properties.

Dry Sliding Wear of Lu2O3 Sialon Ceramics

2006 ◽  
Vol 317-318 ◽  
pp. 351-354
Author(s):  
Mark I. Jones ◽  
Kiyoshi Hirao ◽  
Hideki Hyuga ◽  
Yukihiko Yamauchi
Keyword(s):  
Wear Resistance ◽  
Composite Materials ◽  
Wear Mechanism ◽  
Wear Behaviour ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Wear Properties ◽  
Experimental Conditions ◽  
Wear Rates ◽  
Order Of Magnitude

The effects of microstructure and composition on the wear properties of Lu sialon ceramics have been studied under dry sliding conditions through block-on-ring wear tests. Microstructural and compositional effects on wear behaviour were studied by producing both equiaxed and elongated α sialons through the incorporation of additional oxides to promote extended liquid formation and grain growth, and by producing α / β composite materials with elongated β grains. The wear response of the materials is discussed in terms of the dominant wear mechanism under different experimental conditions. Under higher loads, where fracture dominates, materials with improved mechanical properties show better wear resistance and both the composite materials and the elongated α sialons showed lower wear rates than the equiaxed materials due to the elongated grain microstructures. Under low normal loads, fracture does not occur and the dominant wear mechanism is thought to be tribochemically assisted wear. Under these conditions, the equiaxed materials had better wear resistance than the composites, and the Lu-α sialon showed an order of magnitude lower wear rate than an equivalent Y-α sialon, thought to be due to better oxidation resistance and improved refractory nature afforded through the use of the smaller radius cation. The elongated Lu-α sialons under these low load conditions showed wear resistance that was to some extent dependent on the composition of the additional liquid phase, with high SiO2 contents leading to higher wear rates.

The Influence of Yttrium Rich Intermetallic Phases and Heat Treatment on the Microstructure, Hardness and Wear Properties of Al-15%Mg2Si Composite

2011 ◽  
Vol 471-472 ◽  
pp. 1165-1170 ◽  
Author(s):  
H.R. Jafari Nodooshan ◽  
M. Emamy ◽  
N. Nemati ◽  
A. Bahrami
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Wear Behavior ◽  
Hardness Measurement ◽  
Intermetallic Phases ◽  
Track Length ◽  
Dry Sliding Wear ◽  
Wear Properties ◽  
Wear Rates ◽  
Before And After

This study was undertaken to investigate the effect of different concentrations of Yttrium (0.1, 0.3, 0.5, 1.0 wt.%) and heat treatment on the microstructure, hardness and wear resistance of an in-situ cast composite (Al-15%Mg2Si ). The microstructural study of the composite before and after solution and ageing showed both primary and secondary Mg2Si phases in all specimens and intermetallics containing Y (Al2Y) were visible after Solution at 520 °C for 4 hours. Hardness measurement demonstrates that the addition of Y increases the hardness gradually but a reduction in the hardness of heat treated specimen’s occurs with the addition of Y ( 0.5%Y).Wear tests were performed using a pin on disk apparatus. The MMCs were rubbed against a carbon steel pin under a load of 10 and 20 N at a sliding velocity of 0.1 ms−1; track length of 1500 m. The degree of improvement in dry sliding wear resistance brought about by Y addition is strongly dependent on the formation of Yttrium rich intermetallic phases as well as heat treatment influence and the wear behavior determined through the precise measurement of weight loss of the samples and wear rates. Worn surfaces were analyzed by scanning electron microscopy (SEM).

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